-#!/usr/bin/python
+#
#
# Copyright (C) 2006, 2007 Google Inc.
"""Ganeti small utilities
+
"""
import socket
import tempfile
import shutil
-from errno import ENOENT, ENOTDIR, EISDIR, EEXIST
+import errno
+import pwd
+import itertools
+import select
+import fcntl
+
+from cStringIO import StringIO
from ganeti import logger
from ganeti import errors
+from ganeti import constants
+
_locksheld = []
_re_shell_unquoted = re.compile('^[-.,=:/_+@A-Za-z0-9]+$')
+debug = False
+
class RunResult(object):
"""Simple class for holding the result of running external programs.
else:
self.fail_reason = "unable to determine termination reason"
+ if debug and self.failed:
+ logger.Debug("Command '%s' failed (%s); output: %s" %
+ (self.cmd, self.fail_reason, self.output))
+
def _GetOutput(self):
"""Returns the combined stdout and stderr for easier usage.
def _GetLockFile(subsystem):
"""Compute the file name for a given lock name."""
- return "/var/lock/ganeti_lock_%s" % subsystem
+ return "%s/ganeti_lock_%s" % (constants.LOCK_DIR, subsystem)
def Lock(name, max_retries=None, debug=False):
fd = os.open(lockfile, os.O_CREAT | os.O_EXCL | os.O_RDWR | os.O_SYNC)
break
except OSError, creat_err:
- if creat_err.errno != EEXIST:
+ if creat_err.errno != errno.EEXIST:
raise errors.LockError("Can't create the lock file. Error '%s'." %
str(creat_err))
shell = True
env = os.environ.copy()
env["LC_ALL"] = "C"
+ poller = select.poll()
child = subprocess.Popen(cmd, shell=shell,
stderr=subprocess.PIPE,
stdout=subprocess.PIPE,
close_fds=True, env=env)
child.stdin.close()
- out = child.stdout.read()
- err = child.stderr.read()
+ poller.register(child.stdout, select.POLLIN)
+ poller.register(child.stderr, select.POLLIN)
+ out = StringIO()
+ err = StringIO()
+ fdmap = {
+ child.stdout.fileno(): (out, child.stdout),
+ child.stderr.fileno(): (err, child.stderr),
+ }
+ for fd in fdmap:
+ status = fcntl.fcntl(fd, fcntl.F_GETFL)
+ fcntl.fcntl(fd, fcntl.F_SETFL, status | os.O_NONBLOCK)
+
+ while fdmap:
+ for fd, event in poller.poll():
+ if event & select.POLLIN or event & select.POLLPRI:
+ data = fdmap[fd][1].read()
+ # no data from read signifies EOF (the same as POLLHUP)
+ if not data:
+ poller.unregister(fd)
+ del fdmap[fd]
+ continue
+ fdmap[fd][0].write(data)
+ if (event & select.POLLNVAL or event & select.POLLHUP or
+ event & select.POLLERR):
+ poller.unregister(fd)
+ del fdmap[fd]
+
+ out = out.getvalue()
+ err = err.getvalue()
status = child.wait()
if status >= 0:
try:
os.unlink(filename)
except OSError, err:
- if err.errno not in (ENOENT, EISDIR):
+ if err.errno not in (errno.ENOENT, errno.EISDIR):
raise
try:
f = open("/proc/%d/status" % pid)
except IOError, err:
- if err.errno in (ENOENT, ENOTDIR):
+ if err.errno in (errno.ENOENT, errno.ENOTDIR):
return False
alive = True
return names_filtered[0]
-def LookupHostname(hostname):
- """Look up hostname
+class HostInfo:
+ """Class implementing resolver and hostname functionality
- Args:
- hostname: hostname to look up, can be also be a non FQDN
+ """
+ def __init__(self, name=None):
+ """Initialize the host name object.
- Returns:
- Dictionary with keys:
- - ip: IP addr
- - hostname_full: hostname fully qualified
- - hostname: hostname fully qualified (historic artifact)
+ If the name argument is not passed, it will use this system's
+ name.
- """
- try:
- (fqdn, dummy, ipaddrs) = socket.gethostbyname_ex(hostname)
- ipaddr = ipaddrs[0]
- except socket.gaierror:
- # hostname not found in DNS
- return None
+ """
+ if name is None:
+ name = self.SysName()
- returnhostname = {
- "ip": ipaddr,
- "hostname_full": fqdn,
- "hostname": fqdn,
- }
+ self.query = name
+ self.name, self.aliases, self.ipaddrs = self.LookupHostname(name)
+ self.ip = self.ipaddrs[0]
+
+ def ShortName(self):
+ """Returns the hostname without domain.
+
+ """
+ return self.name.split('.')[0]
- return returnhostname
+ @staticmethod
+ def SysName():
+ """Return the current system's name.
+
+ This is simply a wrapper over socket.gethostname()
+
+ """
+ return socket.gethostname()
+
+ @staticmethod
+ def LookupHostname(hostname):
+ """Look up hostname
+
+ Args:
+ hostname: hostname to look up
+
+ Returns:
+ a tuple (name, aliases, ipaddrs) as returned by socket.gethostbyname_ex
+ in case of errors in resolving, we raise a ResolverError
+
+ """
+ try:
+ result = socket.gethostbyname_ex(hostname)
+ except socket.gaierror, err:
+ # hostname not found in DNS
+ raise errors.ResolverError(hostname, err.args[0], err.args[1])
+
+ return result
def ListVolumeGroups():
key_fields = key.split()
fd, tmpname = tempfile.mkstemp(dir=os.path.dirname(file_name))
- out = os.fdopen(fd, 'w')
try:
- f = open(file_name, 'r')
+ out = os.fdopen(fd, 'w')
+ try:
+ f = open(file_name, 'r')
+ try:
+ for line in f:
+ # Ignore whitespace changes while comparing lines
+ if line.split() != key_fields:
+ out.write(line)
+
+ out.flush()
+ os.rename(tmpname, file_name)
+ finally:
+ f.close()
+ finally:
+ out.close()
+ except:
+ RemoveFile(tmpname)
+ raise
+
+
+def SetEtcHostsEntry(file_name, ip, hostname, aliases):
+ """Sets the name of an IP address and hostname in /etc/hosts.
+
+ """
+ # Ensure aliases are unique
+ aliases = UniqueSequence([hostname] + aliases)[1:]
+
+ fd, tmpname = tempfile.mkstemp(dir=os.path.dirname(file_name))
+ try:
+ out = os.fdopen(fd, 'w')
+ try:
+ f = open(file_name, 'r')
+ try:
+ written = False
+ for line in f:
+ fields = line.split()
+ if fields and not fields[0].startswith('#') and ip == fields[0]:
+ continue
+ out.write(line)
+
+ out.write("%s\t%s" % (ip, hostname))
+ if aliases:
+ out.write(" %s" % ' '.join(aliases))
+ out.write('\n')
+
+ out.flush()
+ os.fsync(out)
+ os.rename(tmpname, file_name)
+ finally:
+ f.close()
+ finally:
+ out.close()
+ except:
+ RemoveFile(tmpname)
+ raise
+
+
+def RemoveEtcHostsEntry(file_name, hostname):
+ """Removes a hostname from /etc/hosts.
+
+ IP addresses without names are removed from the file.
+ """
+ fd, tmpname = tempfile.mkstemp(dir=os.path.dirname(file_name))
+ try:
+ out = os.fdopen(fd, 'w')
try:
- for line in f:
- # Ignore whitespace changes while comparing lines
- if line.split() != key_fields:
+ f = open(file_name, 'r')
+ try:
+ for line in f:
+ fields = line.split()
+ if len(fields) > 1 and not fields[0].startswith('#'):
+ names = fields[1:]
+ if hostname in names:
+ while hostname in names:
+ names.remove(hostname)
+ if names:
+ out.write("%s %s\n" % (fields[0], ' '.join(names)))
+ continue
+
out.write(line)
- out.flush()
- os.rename(tmpname, file_name)
+ out.flush()
+ os.fsync(out)
+ os.rename(tmpname, file_name)
+ finally:
+ f.close()
finally:
- f.close()
- finally:
- out.close()
+ out.close()
+ except:
+ RemoveFile(tmpname)
+ raise
def CreateBackup(file_name):
raise errors.ProgrammerError("Can't make a backup of a non-file '%s'" %
file_name)
- # Warning: the following code contains a race condition when we create more
- # than one backup of the same file in a second.
- backup_name = file_name + '.backup-%d' % int(time.time())
- shutil.copyfile(file_name, backup_name)
+ prefix = '%s.backup-%d.' % (os.path.basename(file_name), int(time.time()))
+ dir_name = os.path.dirname(file_name)
+
+ fsrc = open(file_name, 'rb')
+ try:
+ (fd, backup_name) = tempfile.mkstemp(prefix=prefix, dir=dir_name)
+ fdst = os.fdopen(fd, 'wb')
+ try:
+ shutil.copyfileobj(fsrc, fdst)
+ finally:
+ fdst.close()
+ finally:
+ fsrc.close()
+
return backup_name
return ' '.join([ShellQuote(i) for i in args])
-def _ParseIpOutput(output):
- """Parsing code for GetLocalIPAddresses().
- This function is split out, so we can unit test it.
+def TcpPing(source, target, port, timeout=10, live_port_needed=False):
+ """Simple ping implementation using TCP connect(2).
+
+ Try to do a TCP connect(2) from the specified source IP to the specified
+ target IP and the specified target port. If live_port_needed is set to true,
+ requires the remote end to accept the connection. The timeout is specified
+ in seconds and defaults to 10 seconds
"""
- re_ip = re.compile('^(\d+\.\d+\.\d+\.\d+)(?:/\d+)$')
+ sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
- ips = []
- for line in output.splitlines(False):
- fields = line.split()
- if len(line) < 4:
- continue
- m = re_ip.match(fields[3])
- if m:
- ips.append(m.group(1))
+ sucess = False
+
+ try:
+ sock.bind((source, 0))
+ except socket.error, (errcode, errstring):
+ if errcode == errno.EADDRNOTAVAIL:
+ success = False
- return ips
+ sock.settimeout(timeout)
+ try:
+ sock.connect((target, port))
+ sock.close()
+ success = True
+ except socket.timeout:
+ success = False
+ except socket.error, (errcode, errstring):
+ success = (not live_port_needed) and (errcode == errno.ECONNREFUSED)
-def GetLocalIPAddresses():
- """Gets a list of all local IP addresses.
+ return success
- Should this break one day, a small Python module written in C could
- use the API call getifaddrs().
+
+def ListVisibleFiles(path):
+ """Returns a list of all visible files in a directory.
"""
- result = RunCmd(["ip", "-family", "inet", "-oneline", "addr", "show"])
- if result.failed:
- raise errors.OpExecError("Command '%s' failed, error: %s,"
- " output: %s" % (result.cmd, result.fail_reason, result.output))
+ files = [i for i in os.listdir(path) if not i.startswith(".")]
+ files.sort()
+ return files
+
+
+def GetHomeDir(user, default=None):
+ """Try to get the homedir of the given user.
+
+ The user can be passed either as a string (denoting the name) or as
+ an integer (denoting the user id). If the user is not found, the
+ 'default' argument is returned, which defaults to None.
+
+ """
+ try:
+ if isinstance(user, basestring):
+ result = pwd.getpwnam(user)
+ elif isinstance(user, (int, long)):
+ result = pwd.getpwuid(user)
+ else:
+ raise errors.ProgrammerError("Invalid type passed to GetHomeDir (%s)" %
+ type(user))
+ except KeyError:
+ return default
+ return result.pw_dir
+
+
+def NewUUID():
+ """Returns a random UUID.
+
+ """
+ f = open("/proc/sys/kernel/random/uuid", "r")
+ try:
+ return f.read(128).rstrip("\n")
+ finally:
+ f.close()
- return _ParseIpOutput(result.output)
+
+def WriteFile(file_name, fn=None, data=None,
+ mode=None, uid=-1, gid=-1,
+ atime=None, mtime=None):
+ """(Over)write a file atomically.
+
+ The file_name and either fn (a function taking one argument, the
+ file descriptor, and which should write the data to it) or data (the
+ contents of the file) must be passed. The other arguments are
+ optional and allow setting the file mode, owner and group, and the
+ mtime/atime of the file.
+
+ If the function doesn't raise an exception, it has succeeded and the
+ target file has the new contents. If the file has raised an
+ exception, an existing target file should be unmodified and the
+ temporary file should be removed.
+
+ """
+ if not os.path.isabs(file_name):
+ raise errors.ProgrammerError("Path passed to WriteFile is not"
+ " absolute: '%s'" % file_name)
+
+ if [fn, data].count(None) != 1:
+ raise errors.ProgrammerError("fn or data required")
+
+ if [atime, mtime].count(None) == 1:
+ raise errors.ProgrammerError("Both atime and mtime must be either"
+ " set or None")
+
+
+ dir_name, base_name = os.path.split(file_name)
+ fd, new_name = tempfile.mkstemp('.new', base_name, dir_name)
+ # here we need to make sure we remove the temp file, if any error
+ # leaves it in place
+ try:
+ if uid != -1 or gid != -1:
+ os.chown(new_name, uid, gid)
+ if mode:
+ os.chmod(new_name, mode)
+ if data is not None:
+ os.write(fd, data)
+ else:
+ fn(fd)
+ os.fsync(fd)
+ if atime is not None and mtime is not None:
+ os.utime(new_name, (atime, mtime))
+ os.rename(new_name, file_name)
+ finally:
+ os.close(fd)
+ RemoveFile(new_name)
+
+
+def all(seq, pred=bool):
+ "Returns True if pred(x) is True for every element in the iterable"
+ for elem in itertools.ifilterfalse(pred, seq):
+ return False
+ return True
+
+
+def any(seq, pred=bool):
+ "Returns True if pred(x) is True for at least one element in the iterable"
+ for elem in itertools.ifilter(pred, seq):
+ return True
+ return False
+
+
+def UniqueSequence(seq):
+ """Returns a list with unique elements.
+
+ Element order is preserved.
+ """
+ seen = set()
+ return [i for i in seq if i not in seen and not seen.add(i)]
+
+
+def IsValidMac(mac):
+ """Predicate to check if a MAC address is valid.
+
+ Checks wether the supplied MAC address is formally correct, only
+ accepts colon separated format.
+ """
+ mac_check = re.compile("^([0-9a-f]{2}(:|$)){6}$")
+ return mac_check.match(mac) is not None
projects / ganeti-local / blobdiff